Light string and light string circuits

ABSTRACT

A light string includes an illumination device, a first wire, a second wire, soldering material, and transparent adhesive. The illumination device includes two soldering portions. The conductors of the first wire and the second wire are partially exposed to form a first soldering section and a second soldering section. Soldering material is used to attach the first soldering section and the second soldering section to the two soldering portions. The transparent adhesive forms a layer over, and covers, the illumination device, the first soldering section and the second soldering section, and extends to partially cover other portions of the first wire and the second wire.

PRIORITY CLAIM

This application is a continuation of U.S. patent application Ser. No.16/874,848, filed May 15, 2020, which is a continuation of U.S. patentapplication Ser. No. 16/219,657, filed Dec. 13, 2018, which claims thebenefit of U.S. Provisional Patent Application No. 62/598,288, filedDec. 13, 2017, the contents of which are incorporated herein byreference in their entireties.

FIELD OF THE INVENTION

The instant disclosure relates to decorative light strings, and inparticular, relates to light strings, circuits of light strings, andmethods of manufacturing light strings.

BACKGROUND OF THE INVENTION

A light string that includes plural light sources directly soldered ontoelectric conductors at intervals, so as to form a string-shapedillumination device without a lamp holder, is known in the art. Anexample of such a light string is found in U.S. Pat. No. 8,397,381,entitled Method of Manufacturing Light Set with Surface Mounted LightEmitting Components. Light strings having many small-sized lightsources, such as small bulbs that include light emitting diodes (LEDs),are commonly known. A light string is as flexible as the electric wireis, such that the light string is easily arranged in any configurationto comply with requirements for special illumination or decoration.

In the art, light sources are soldered to the copper core or conductorafter the insulating layer of the electric wire or wire is removed, andthen an electrical insulating treatment is performed on the solderjoints. In this approach, light sources obviously stick out on theelectric wire and are configured to have high-directivity. Whenarranging a light string, which may include pulling the light string,the light sources may be subject to forces and shocks that result insolder joints cracking. Furthermore, usually electric wires areflexible, but the soldering material is not as flexible. Thus, when theelectric wire of the light string is pulled or bent, stressconcentration often occurs at the soldering joints and results insoldering joints cracking.

In addition, in a light string, light sources are typically electricallyconnected in series or electrically connected in parallel. In parallel,precise driving voltage is required to drive the light source andprevent the light sources from being damaged by over-current. In aseries connection, the number of the light sources is determined by theoutput voltage of the power source, with the number and type of lightsource being selected to ensure that every light source is driven by anappropriate voltage with an allowable voltage difference. This meansthat the number of the light sources is restricted by the output of thepower source such that the number cannot be changed at will. Meanwhile,one damaged light can result in failure of the whole light string.

SUMMARY OF THE INVENTION

The present disclosure provides embodiments of light strings, systemsand circuits thereof, as well as methods of manufacturing light strings,that present an improvement over known light strings and relatedsystems, circuits, and methods of manufacturing.

According to an embodiment of the present disclosure, a light stringincludes at least one illumination device, a first wire and a secondwire.

The illumination device includes a substrate and a light source; whereinthe substrate includes a carrier portion and two soldering portions, thecarrier portion is located between the two soldering portions, and thelight source is disposed on the carrier portion. The first wire includesa first conductor, which may comprise one or more conductive strands,and a first insulating layer; wherein the first insulating layer wrapsaround the first conductor and the first conductor is partially exposedto form at least one first soldering section. The second wire includes asecond conductor and a second insulating layer; wherein the secondinsulating layer wraps around the second conductor, and the secondconductor is partially exposed to form at least one second solderingsection. The first soldering section and the second soldering sectionare attached to the two soldering portions of the substraterespectively; and the light source is located between the firstsoldering section and the second soldering section. The solderingmaterial is disposed onto the two soldering portions and at leastpartially covers the first soldering section and the second solderingsection, so as to attach the first soldering section and the secondsoldering section to the two soldering portions respectively. In anembodiment, a transparent covering, such as an adhesive, which may beglue, covers the illumination device, the first soldering section andthe second soldering section, and extends to partially cover the firstinsulating layer and the second insulating layer. In an embodiment, thetransparent glue has a largest cross-sectional area in an areacorresponding to the light source, and the cross-sectional area of thetransparent glue shrinks gradually along a direction toward the firstinsulating layer and the second insulating layer.

According to another embodiment of the present disclosure, a circuit oflight string includes a first wire, a second wire, and a plurality ofillumination devices.

Each of the illumination devices includes a substrate and a lightsource. The substrate includes a carrier portion, an anode solderingportion and a cathode soldering portion, the carrier portion is locatedbetween the anode soldering portion and the cathode soldering portion,and the light source is disposed on the carrier portion and electricallyconnected to the anode soldering portion and the cathode solderingportion. The illumination devices are electrically connected to thefirst wire and the second wire by the anode soldering portions and thecathode soldering portions.

According to yet another embodiment of the present disclosure, a circuitof a light string includes a first wire, a second wire, a plurality ofillumination devices, and a third wire.

In an embodiment, each of the illumination devices includes a substrate,a light source and a controller; wherein the substrate includes acarrier portion, an anode soldering portion and a cathode solderingportion, the carrier portion is located between the anode solderingportion and the cathode soldering portion, and the light source isdisposed on the carrier portion, and electrically connected to the anodesoldering portion and the cathode soldering portion; the controller iscombined with the substrate for enabling and disabling the light source,and the controller includes a signal-input terminal and a signal-outputterminal; and each of the illumination devices are electricallyconnected to the first wire by the anode soldering portions, andelectrically connected to the second wire by the cathode solderingportions. The third wire includes a signal-input end and a signal-outputend, and a plurality of cut-off points are arranged on the third wire.Each of the illumination devices is disposed at one of the cut-offpoints respectively, and the signal input terminal and the signal outputterminal are electrically connected to the third wire respectively viadifferent sides of the corresponding cut-off point. The third wirereceives a control signal from the signal input end, and transfers thecontrol signal to each of the controllers via the signal input terminalsto control the corresponding light source, and the control signal istransferred to the controller of the next illumination device via thesignal output terminals.

In the present disclosure, the illumination devices are securelysoldered between the first wire and the second wire, and provide goodillumination effect. Moreover, embodiments of circuits of light stringsin the present disclosure provide a variety of approaches to supplyingpower, adopt various types of light source, and ensure that every lightsource can receives acceptable power input to prevent under voltageresulting from too many light sources.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will become more fully understood from thedetailed description given herein below for illustration only, and thusnot limitative of the present invention, wherein:

FIG. 1 is an exploded view of a first wire, a second wire and anillumination device, according to a first embodiment of the presentdisclosure;

FIG. 2 is a three-dimensional view of the first wire, the second wireand the illumination device combined together, according to the firstembodiment of the present disclosure;

FIG. 3 is a three-dimensional view of a light string, according to thefirst embodiment of the present disclosure;

FIG. 4 is a cross-sectional view of the first wire, the second wire andthe illumination device combined together according to the firstembodiment of the present disclosure;

FIG. 5 is a cross-sectional view of the light string according to thefirst embodiment of the present disclosure;

FIG. 6 is a circuit diagram of a circuit of light string according to asecond embodiment of the present disclosure;

FIG. 6A is a depiction of a light string having the circuit of FIG. 6,according to an embodiment of the present disclosure;

FIG. 6B is a simplified cross-sectional view of the light string of FIG.6A;

FIG. 7 and FIG. 8 are circuit diagrams of a circuit of light stringaccording to a third embodiment of the present disclosure;

FIG. 9 is a circuit diagram of a circuit of light string according to afourth embodiment of the present disclosure;

FIG. 9A is a depiction of a light string having the circuit of FIG. 9,according to an embodiment of the present disclosure;

FIG. 9B is a view of a portion of the light string of FIG. 9A, accordingto an embodiment of the present disclosure;

FIG. 10 and FIG. 11 are circuit diagrams of a circuit of a light stringaccording to a fifth embodiment of the present disclosure; and

FIG. 12 is a top view of an illumination device according to the fifthembodiment of the present disclosure.

DETAILED DESCRIPTION

Referring to FIG. 1, FIG. 2 and FIG. 3, a light string 100 includes oneor more illumination devices 130, a first wire 110, a second wire 120,soldering material 140 and transparent adhesive 150.

Referring to FIGS. 1-4, although only one illumination device 130 isillustrated in the drawings, the light string 100 in the presentdisclosure can be equipped with two or more than two illuminationdevices 130 and disposed between the first wire 110 and the second wire120 in parallel. Each of the illumination devices 130 includes asubstrate 131 and a light source 132. The substrate 131 includes acarrier portion 133 and two soldering portions 134. The carrier portion133 is located between the two soldering portions 134, and the lightsource 132 is disposed on the carrier portion 133.

At least the surface of each of the soldering portions 134 is comprisedof a conductive material 135 and respectively connected to the lightsource 132. In one example, a metal layer is plated on each of thesoldering portions 134, to serves as the conductive material 135. Inanother example, each of the soldering portions 134 is made of metal,and the substrate 131 is formed by joining the insulation part (thecarrier portion 133) and the conductive part (the soldering portions134).

Referring to FIG. 4, the light source 132 further includes alight-emitting component 136 and a transparent package body 137. Thelight-emitting component 136 is disposed on the carrier portion 133 ofthe substrate 131, and the transparent package body 137 covers thelight-emitting component 136.

In one example, the illumination device 130 is a surface-mounttechnology light-emitting diode (SMT LED). The light-emitting component136 is a light-emitting diode chip. The substrate 131, in an embodiment,is a sapphire substrate. The transparent package body 137, in anembodiment, is composed of solidified glue or adhesive, wherein liquidglue is dispensed on the light-emitting diode chip and solidified toform the transparent package body 137. A convex portion is formed on theupper surface of the transparent package body 137 to increase the beamangle and the brightness of illumination. In an embodiment, the liquidglue is a resin encapsulation glue containing phosphor, and theproportion of phosphor to the rest of the liquid glue determines thefluidity of the liquid glue and the curvature of the convex.

Referring to FIG. 1, FIG. 2 and FIG. 4, the first wire 110 includes afirst conductor 112 and a first insulating layer 114. In an embodiment,conductor 112 comprises a single strand conductor, and in otherembodiments, comprises multiple strands, which may be twisted about oneanother. The first insulating layer 114 wraps around the first conductor112, and the first conductor 112 is partially exposed to form at leastone first soldering section 116. During a manufacturing process, firstsoldering section 112 and second soldering section 116 may be formed ina variety of ways. In an embodiment, an axial (lengthwise) pull force ortension is applied to wires 100 and 120, then a portion of insulatinglayers 114 and 124 are cut, in some cases circumferentially, withoutcutting the conductors, causing portions of the insulating layers 114and 124 to move axially along the respective conductors, exposing aportion of the conductors of the wires, thereby creating first solderingsection 112 and second soldering section 116. In an embodiment, thenumber of first soldering sections 116 is equal to the number of theillumination devices 130.

As shown in FIG. 1, FIG. 2 and FIG. 4, the second wire 120 includes asecond conductor 122 and a second insulating layer 124. The secondinsulating layer 124 wraps around the second conductor 122, and thesecond conductor 122 is partially exposed to form at least one secondsoldering section 126. In an embodiment, the number of second solderingsections 126 is equal to the number of illumination devices 130, andeach first soldering section 116 is paired with a second solderingsection 126.

In an embodiment, and as shown in FIG. 2 and FIG. 4, the first solderingsection 116 and the second soldering section 126 are attached to the twosoldering portions 131 of the substrate 134 respectively, and the lightsource 132 is disposed between the first soldering section 116 and thesecond soldering section 126, such that the first soldering section 116and the second soldering section 126 hold the illumination device 130and its light source 132 in a clamping manner. In such an embodiment,wires 110 and 120 impart a retaining force in a direction perpendicularto a lengthwise axis of the wires, on illumination devices 130, whichaids in retaining each illumination device 130 in contact with solderingsections 116 and 126.

As shown in the drawings, the soldering material 140 is disposed ontothe two soldering portions 134 and partially covers the first solderingsection and the second soldering section, to attach the first solderingsection 116 and the second soldering section 126 to the two solderingportions 134 respectively. In an embodiment, to prevent solder joints onthe first soldering section 116 and the second soldering section 126from cracking, the soldering material 140 further extends to cover alateral edge and a back surface of the substrate 131, and surfaces ofthe lateral edge and the back surface are comprised of the conductivematerial 135 as well. Such a method of soldering causes conductivejoining of a greater conductive area of the soldering sections of theconductors of the wire, and a larger conductive area of the solderingportions of the illumination device. The result is a stronger mechanicalbond, which results in a higher quality, more durable light set, andalso avoids known non-wetting issues that may arise in solder jointsaccomplished by other manufacturing methods.

As shown in FIG. 1 and FIG. 2, in an embodiment, the transparentadhesive or glue layer 150 covers the illumination device 130, the firstsoldering section 116 and the second soldering section 126, and furtherextends to partially cover the first insulating layer 114 and the secondinsulating layer 124. The transparent glue 150 has a largestcross-sectional area at a location corresponding to the light source132.

The cross-sectional area of the transparent glue 150 shrinks graduallyalong directions toward the first insulating layer 114 and the secondinsulating layer 124. That is, the transparent glue bulk 150 not onlycovers the illumination device 130, the first soldering section 116 andthe second soldering section 126, but also covers the sections of thefirst second insulating layer 114 and the second insulating layer 124which are adjacent to the transparent glue layer 150.

The material of the transparent adhesive 150 can comprise rapidsolidification glue such as a UV cure adhesive. During manufacture,liquid glue is dispensed onto the light source 132 by a glue dispenser,and then the liquid glue flows over the top of the light source 132 andinto the adjacent sections of the first insulating layer 114 and secondinsulating layer 124.

Referring FIG. 4, the transparent glue 150 extends to partially coverthe first insulating layer 114 and the second insulating layer 124. Inan embodiment, the transparent glue 150 when solidified is tough and mayhave a hardness higher than a hardness of any portion of the first wire110 or the second wire 120. Therefore, when the first wire 110 or thesecond wire 120 is bent for arrange the light string 100, the section ofthe first wire 110 or the second wire 120 equipped with the illuminationdevice 130 will not be bent, so as to prevent solder joints on the firstsoldering section 116 or the second soldering section 126 from crackingdue to bending stress. Moreover, the transparent glue layer 150 alsoserves as a light guide device, so as to significantly increase the beamangle of the light source 132.

Referring to FIG. 5, when the first wire 110 and the second wire 120 arepulled, the first soldering section 116 and the second soldering section126 press against the illumination device 130 with only minimal shearstress between the soldering portions 134 and the first solderingsection 116 or between the soldering portions 134 and the secondsoldering section 126. Therefore, the light string 100 also preventssolder joints on the first soldering section 116 or the second solderingsection 126 from cracking due to shear stress.

That is, the coverage of the transparent glue layer 150 strengthens thelight string 100 to withstand bending stress, and the arrangement of thefirst soldering section 116, the second soldering section 126 and theillumination device 130 strengthens the light string 100 to withstandshear stress.

In an embodiment, the first conductor 112 and/or the second conductor122 may be solid, single-strand conductors (single piece copperconductor or metal conductor made of an appropriate conductive metal,such as copper, a copper alloy, and so on) as is depicted in FIG. 1 toFIG. 5. Alternatively, the first conductor 112 and/or the secondconducting wire 122 may comprise stranded conductors instead of a singlepiece conductor. In the first embodiment, the first second insulatinglayer 114 and the second insulating layer 124 are respectively plasticinsulators, such as polyvinylchloride (PVC). In one or more embodiments,the first insulating layer 114 and the second insulating layer 124 arevery thin layers of insulation, such as an enamel coating, such that thefirst wire 110 or the second wire 120 are enameled wires. In one or moreembodiments, the first insulating layer 114 and the second insulatinglayer 124 are combined into one piece for convenience of wirearrangement.

Referring to FIGS. 6, 6A and 6B, features of a 3-wire light string 100and circuit 2 are depicted. FIG. 6 depicts an electrical schematic of acircuit 2; FIG. 6A depicts an embodiment of a 3-wire light string 100;and FIG. 6B depicts a simplified cross-sectional view of light string100. Although FIG. 6B depicts an embodiment of illumination device 130positioned on top of conductors 112, 116 and 162 for the sake ofillustrating the basic electrical connections of illumination device 130with wires 110, 120 and 160, it will be understood that otherembodiments of light string 100 are consistent with the previousdescription and depictions of illumination device 130 being attached“below” or between the respective conductors.

Referring to FIG. 6, a circuit 2 of the light string 100 is depictedaccording to a second embodiment of the present disclosure. In theembodiment of FIG. 6, multiple illumination devices 130 are arranged inseries and parallel on three wires to form light string 100.

As depicted in FIGS. 6, 6A and 6B, the circuit 2 in the secondembodiment includes a first wire 110, a second wire 120, a third wire160 and a plurality of illumination devices 130. Third wire 160 includesconductor 162 and insulation layer 164.

The first wire 110 is used to receive a first electric potential V1; andin one example, the first electric potential is 6V direct current (DC).The third wire 160 is used to receive a third electric potential V3; andin one example the third electric potential V3 is ground potential(GND). The second wire 120 is used as a connection node among theillumination devices 130.

In an embodiment, each of the illumination devices 130 is substantiallyidentical to the illumination device 130 in the first embodiment. In thesecond embodiment, the soldering portions 134 of each illuminationdevice 130 are sorted into an anode soldering portion (+) and a cathodesoldering portion (−) according to the polarity of the light source 132(in particular to the LED polarity). The carrier portion 133 asdescribed in the first embodiment is located between the anode solderingportion (+) and the cathode soldering portion (−) and the light source132 is disposed on the carrier portion 133 and electrically connected tothe anode soldering portion (+) and the cathode soldering portion (−).

As depicted in FIG. 6, some of the illumination devices 130 areelectrically connected to the first wire 110 at the anode solderingportions (+) and electrically connected to the second wire 120 at thecathode soldering portions (−). The other illumination devices 130 areelectrically connected to the second wire 120 at the anode solderingportions (+) and electrically connected to the third wire 160 at thecathode soldering portions (−).

Therefore, the illumination devices 130 are sorted into two groups. Inthe first group, the illumination devices 130 are electrically connectedin parallel by connection to the first wire 110 and the second wire 120respectively. In the second group, the illumination devices 130 areelectrically connected in parallel by connected to the second wire 120and the third wire 130 respectively.

The first group is electrically connected to the second group in seriesvia the second wire 120.

As shown in FIG. 6, in an embodiment, the circuit 2 further includes acurrent-limiting resistor 180, electrically connecting the firstelectric potential V1 to the first wire 110 for limiting current in thefirst wire 110. The current-limiting resistor 180 limits the current inthe first wire 110, so as to prevent the illumination devices 130 frombeing damaged by over-current. In an embodiment, a section of aconductor of the wire is cut out, or the conductor is otherwise cut orinterrupted, and a resistor may be soldered between the two resultingends of the conductor.

In the second embodiment, the first wire 110, the second wire 120 andthe third wire 130 are arranged in parallel. In one such embodiment, theinsulating layers of the first wire 110, the second wire 120 and thethird wire 160 can be combined together into a unitary layer and onlythe sections of the wires on which the illumination devices 130 aredisposed need have insulation removed. Therefore, the circuit 2 becomesa long single-piece light string for convenience of wires arrangement.

Referring to FIG. 7 and FIG. 8, a circuit 3 of the light stringaccording to a third embodiment includes a first wire 110, a second wire120, a third wire 160 and a plurality of illumination devices 130. Thecircuit 3 further includes a third cut-off point C3, a second cut-offpoint C2 and a first cut-point C1 to form the circuit loop in the thirdembodiment. Cut-off points are points along a length of the wire whereinthe conductor is “broken” or interrupted, such that the conductor of thewire is not contiguous. In an embodiment, a portion of the conductor isremoved to achieve a discontinuity; in other embodiments, the conductoris simply cut. In the latter embodiment, lengthwise tension on theconductor may cause a gap between ends of the conductor, oralternatively, portions of the conductor may be bent away from oneanother to form a gap.

As shown in FIG. 7, the first wire 110, the second wire 120 and thethird wire 130 are arranged in parallel to an extension direction L; inone embodiment, the three wires are single metal wires or strandedconductors combined together by a one-piece insulating layer. Theone-piece insulating layer may comprise a uniform or non-uniform layerthickness. In an embodiment, a portion of a think connecting layer joinsany two conductors together.

The third cut-off point C3, the second cut-off point C2 and the firstcut-point C1 are arranged sequentially along the extension direction L,respectively breaking conductive continuity of the third wire 160, thesecond wire 120 and the first wire 110 so as to divide the circuit 3into a plural of sections based on the third cut-off point C3, thesecond cut-off point C2 and the first cut-off point C1.

In an embodiment of FIG. 7, each of the illumination devices 130 issubstantially identical to the illumination device 130 in the firstembodiment or the second embodiment. Each of the illumination devices130 includes a substrate 131 and a light source 132. The substrate 131includes a carrier portion 133, an anode soldering portion (+) and acathode soldering portion (−). The carrier portion 133 is locatedbetween the anode soldering portion (+) and the cathode solderingportion (−). The light source 132 is disposed on the carrier portion133, and electrically connected to the anode soldering portion (+) andthe cathode soldering portion (−).

Referring to FIG. 8, the illumination devices 130 are sorted intogroups. The first group of the illumination devices 130 are arrangedbefore the first cut-off point C1 along the extension direction L, whichis a longitudinal direction, (starting from the left side of FIG. 8),electrically connected to the first wire 110 by the anode solderingportions (+), and electrically connected to the second wire 120 by thecathode soldering portions (−). First wire 110 defines a first end 110 aand a second end 110 b, a first wire segment 110 c and a second wiresegment 110 d; second wire 120 defines a first end 120 a and a secondend 120 b, a first wire segment 120 c and a second wire segment 120 d;and third wire 160 defines a first end 160 a and a second end 160 b, afirst wire segment 160 c and a second wire segment 160 d.

Referring to FIG. 8, the second group of the illumination devices 130are arranged between the third cut-off point C3 and the second cut-offpoint C2 along the extension direction L, electrically connected to thesecond wire 120 by the anode soldering portions (+), and electricallyconnected to the third wire 160 by the cathode soldering portions (−).

Referring to FIG. 8, the third group of the illumination devices 130 arearranged after the second cut-off point C2 along the extension directionL, electrically connected to the second wire 120 by the cathodesoldering portions (−), and electrically connected to the third wire 160by the anode soldering portions (+).

The fourth group or the rest of the illumination devices 130 arearranged after the first cut-off point C1 and the second cut-off pointC2 along the extension direction L electrically connected to the firstwire 110 by the cathode soldering portions (−), and are electricallyconnected to the second wire 120 by the anode soldering portions (+).

With such an approach, the illumination devices 130 are sorted into fourgroups. In the first group, the illumination devices 130 areelectrically connected in parallel by connected to the first wire 110and the second wire 120 respectively. In the second group, theillumination devices 130 are electrically connected in parallel byconnection to the second wire 120 and the third wire 130 respectively.

Meanwhile, the first group is electrically connected to the second groupin serial via the second wire 120.

In the third group, the illumination devices 130 are electricallyconnected in parallel by connection to the second wire 120 and the thirdwire 130 respectively.

The polarity of the third group is opposite to the second group, and thesecond wire 120 between the second group and the third group is cut offby the second cut-off point C2. Therefore, the third group ofillumination devices 130 is serially connected to the second group ofillumination devices 130. Similarly, in the fourth group, theillumination devices 130 are electrically connected in parallel byconnection to the first wire 110 and the second wire 120 respectively.The polarity of the fourth group is opposite to the first group, and thefirst wire 120 between the first group and the fourth group is cut offby the first cut-off point C1. Therefore, the fourth group ofillumination devices 130 is serially connected to the third group ofillumination devices 130.

Still referring to FIG. 8, one end of the first wire 110 receives afirst electric potential V1; and in one example, the first electricpotential is an alternating current (AC) voltage, such as 110V or 220V.In an embodiment, the other end of the first wire 110 is electricallyconnected to a boost line 170. A boost potential V4 is provided by theboost line 170 according to the electric potential of the first wire 110and required drive voltage for driving the four groups of illuminationdevices 130, so as to boost the voltage applied to each illuminationdevice 130. Generally, the longer the wire, the greater the powerconsumed by the LEDs, and the greater the potential to have an overallvoltage drop delivered to the LEDs furthest from the connection point ofthe power source. Such a situation can cause some illumination devices130 to receive a lower voltage than other devices 130, causing adisparity in light output. A solution according to an embodiment is toconnect a boost line 170 as described herein.

Similarly, in the third embodiment, the first wire 110, the second wire120, the third wire 130 and the boost line 170 are arranged in parallel,the circuit 3 becomes a long single piece light string for convenienceof wires arrangement.

Still referring to FIG. 8, in an embodiment, the circuit 3 furtherincludes a current-limiting resistor 180, electrically connecting thefirst electric potential V 1 to the first wire 110 for limiting currentin the first wire 110. The current-limiting resistor 180 limits thecurrent in the first wire 110, so as to prevent the illumination devices130 from being damaged by over-current. Alternatively, thecurrent-limiting resistor 180 is disposed on the boost line 170, whichis also located on the serial current loop to limit the current thereon.

Referring to FIGS. 9, 9A and 9B, a circuit 4 of the light string isshown according to a fourth embodiment of the present disclosure.

The circuit 4 includes a first wire 110, a second wire 120, a boost line170 and a plurality of illumination devices 130.

The first wire 110 is used to receive a first electric potential V1; andin an embodiment, the first electric potential is 3V direct current(DC). The second wire provides a second electric potential V2 and in oneexample the second electric potential V2 is ground potential (GND). Andthe boost line 170 receives a boost potential V4.

Similar to the first embodiment, each of the illumination devices 130includes a substrate 131 and a light source 132. The substrate 131includes a carrier portion 133, an anode soldering portion (+) and acathode soldering portion (−). The carrier portion 133 is locatedbetween the anode soldering portion (+) and the cathode solderingportion (−). The light source 132 is disposed on the carrier portion133. The detailed description of each illumination device 130 isdescribed in the first embodiment. In the fourth embodiment, each of theillumination devices 130 are electrically connected to the first wire110 by the anode soldering portions (+) and electrically connected tothe second wire 120 by the cathode soldering portions (−). The boostline 170 is electrically connected to the second wire 120.

By such an approach, the illumination devices 130 are electricallyconnected in parallel between the first wire 110 and the second wire120, and the illumination devices 130 are normally driven by the voltagedifference between the first wire 110 and the second wire 120. A boostpotential V4 is provided by the boost line 170 according to the electricpotential of the first wire 110 and required drive voltage for drivingthe illumination devices 130, so as to boost the voltage applied to eachillumination device 130.

Similarly, in the fourth embodiment, the first wire 110, the second wire120 and the boost line 170 are arranged in parallel, the circuit 3becomes a long single-piece light string based on the convenientjoined-wire arrangement.

In an embodiment, boost line 170 is electrically connected to wire 120.In one such embodiment, and also referring to FIG. 9B, boost line 170comprises a portion of wire 120 that is bent at bend 180, such that wire120 extends away from a power source, then back towards the powersource. In another embodiment, boost line 170 comprises a separate anddistinct wire that is electrically connected to wire 120.

In an embodiment, the circuit 4 further includes a current-limitingresistor 180, electrically connecting the first electric potential V1 tothe first wire 110 for limiting current in the first wire 110. Thecurrent-limiting resistor 180 limits the current in the first wire 110,so as to prevent the illumination devices 130 from being damaged byover-current. Alternatively, the current-limiting resistor 180 isdisposed on the boost line 170, which is also located on the serialcurrent loop to limit the current thereon.

Referring to FIG. 10 and FIG. 11, a circuit 5 of the light string isshown according to a fifth embodiment of the present disclosure.

The circuit 5 includes a first wire 110, a second wire 120, a pluralityof illumination devices 130, and a third wire 160.

Referring also to FIG. 12, each of the illumination devices 130 may besubstantially identical to the illumination device 130 in the firstembodiment or the other embodiment. Each of the illumination devices 130includes a substrate 131 and a light source 132. The substrate 131includes a carrier portion 133, an anode soldering portion (+) and acathode soldering portion (−). The carrier portion 133 is locatedbetween the anode soldering portion (+) and the cathode solderingportion (−). The light source 132 is disposed on the carrier portion133, each of the illumination devices 130 a are electrically connectedto the first wire 110 by the anode soldering portions (+) andelectrically connected to the second wire 120 by the cathode solderingportions (−). The detail of the illumination devices 130 is described inthe first embodiment.

The difference of the illumination devices 130 a in the fifth embodimentis that the illumination devices 130 a may further include a controller138; the controller 138 is combined with the substrate 131 for enablingand disabling the light source 132. The controller 138 includes a signalinput terminal DI and a signal output terminal DO;

Referring to FIG. 10 and FIG. 11, the first wire 110 is used to receivea first electric potential V1; and in one example, the first electricpotential is 5V DC. The second wire provides a second electric potentialV2, and in one example the second electric potential V2 is GND. Thethird wire 160 includes a signal input end DATA IN and a signal outputend DATA OUT, and a plurality of cut-off points C being arranged on thethird wire 160. Each of the illumination devices 130 is disposed at oneof the cut-off points C respectively, and the signal input terminal DIand the signal output terminal DO are electrically connected to thethird wire 160 respectively via different sides of the correspondingcut-off point C. The signal input terminal DI corresponds to the signalinput end DATA IN of the third wire 160. The signal output terminal DOcorresponds to the signal output end DATA OUT of the third wire 160.

The third wire 160 receives control signals for enabling and disablingthe light source 132 via the signal input end DATA IN. The third wire160 transfers the control signals to the controller 138 via the signalinput terminal DI for controlling the corresponding light source 138,and then the control signal is transferred to the controller 138 of thenext illumination device 130 a via the signal output terminal DO.Finally, the control signals are transferred to the circuit 5 of anotherlight string.

As shown in FIG. 11, in an embodiment, the circuit 5 further includes acurrent-limiting resistor 180, electrically connecting the firstelectric potential V1 to the first wire 110 for limiting current in thefirst wire 110. The current-limiting resistor 180 limits the current inthe first wire 110, so as to prevent the illumination devices 130 frombeing damaged by over-current.

In the present disclosure, the illumination devices 130 are securelysoldered between the first wire 110 and the second wire 120, and providea good illumination effect. Moreover, the circuit of light string in thepresent disclosure provides a variety of approaches of power supply toadopt various type of light source, and ensures every light source canreceive acceptable power input to prevent under voltage resulting fromtoo many light sources.

What is claimed is:
 1. A light set having at least two wires and aplurality of light-emitting diodes.